Editing custom workflows with Workflow Re-hosting

Question

I've been prototyping this Workflow editor for end users and I've based my source from [MSDN]http://msdn.microsoft.com/en-us/library/aa480213.aspx. So far, I've made the following tweaks:

1. I've added a new project called Workflow.Core which will house custom activities and default workflows.
2. The toolbox now shows custom activities that are included in Workflow.Core.
3. On load, the workflow designer will show a default workflow from Workflow.Core instead of an empty SequentialWorkflowActivity. Aside from defining the initial flow of activities, the default workflow contains properties that are set and modified during workflow runtime.

The problem is that WorkflowView wont let me edit the default workflow. It's like it's in read-only mode, although I can still edit its attributes. It worked fine when I was loading an instance of SequentialWorkflowActivity.

Then I tried adding the default workflow's activities to an instance of SequentialWorkflowActivity and load that instead. It worked. I was able to drag new activities onto it and make property changes. But in doing so, the referenced properties within the default workflow are no longer available.

There is an alternative: that I make and include an activity to house all properties instead of the default workflow itself. It, however, will need explaining to the client (whom I don't think will understand) why there's an omnipresent activity in all their custom workflows which does no discernible business logic.

In summary, I need to make workflow designer edit the default workflows. So if you guys have any ideas or suggestions, please let me know. I need all the help I can get.

Thanks in advanced!

Carlos